Exhaust-silencer.



PATENTED MAR. l0, 1903.

M. CRAWFORD.

EXHAUST SILENOBR.

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UNITED STATES vPATENT OFFICE.

MIDDLETON CRAWFORD, OF LONDON, ENGLAND, ASSIGNOR TO SILENT MOTOR OAR SYNDICATE, LIMITED, LONDON, ENGLAND.

EXHAUST-en l-NGERQ SPECIFICATION forming part of Letters Patent No. 722,567, dated March A10, .1903.

lApplication filed December 3, 1901. Serial No. 84,569. (No model.) l

To all whom t may concern.-

Beit known that I, MIDDLETON CRAWFORD, a subject of the King of England, residing at London, England, have invented certain new and useful Improvements in or Relating to Exhaust-Silencers, (for which I have made v application for Letters Patent in Great Britain und'er No. 9,452, dated May 7, 1901,) of which the following is a specification.

This invention relates to the silencing of the exhaust of engines, and refers more particularly to internal-combustion engines, because with such engines not only is a silencing of the noise of the exhaust obtained, but a scavenging action is produced in the cylinder, which in such engines is of the greatest importance.

According to this invention I employ any desired number of chambers or compartments to which Ytheexhaust-gases from the cylinder are admitted, and these chambers or compartments may bearranged successively as entirely separate vessels connected together by suitable conduits or pipes or .they may be arranged concentrically or otherwise combined to suit requirements.

An important feature of the invention is the employment of an automatic non-return valve, which may be placed in any portion of the exhaust system; but where the chambers are arranged successivelyY or .in series I prefer to place the valve between two of them, either in the pipes between the chambers or at the end of one chamber, so as to control the passage of the exhaustgases into the next. f

Referring to the drawings, Figure l is a longitudinal section, Figj2 a transverse section on the line 2 2, and Fig. 3 a transverse section on the line 3 3, showing the preferred form of an exhaust-silencer constructed in accordance with this invention.

A is the expansion-chamber or chamber Y into which the gases pass from the cylinder preferA to employ double Walls, it is obvious that the same' result may be obtained by merely lagging or lapping the walls of the chamber with some substance which tends to minimize or entirely obviate vibration.

End'or cover plates A3 A1 are provided at one end of the chamberY and formed at their outer edges with annular flanges A5, which engage the ends of the inner and outer walls to form a tight joint. These plates ,are secured in position by bolts A6, which -pass longitudinally through the chamber andare secured rmly in position by nuts A1, screwed onto the ends of the bolts. An inlet-pipe AS is secured to the inner end plate A4 by studs A10, which pass through iiangesA9 on the end of the pipe.

kFrom the chamberA exhaust-gases pass by an opening formed in the endv plate A11v of the chamber, the plate being provided with annular iianges A12V to receive the ends of the double walls of the chamber between them to form a tight joint. The cylindrical valve VB is situated in the opening and has its inner end B? open, or it may be provided with per- `forat-ions through which the gases pass into the interior of the valve. Openings B3 are providedin the walls of the valve to permit the gases to pass into the inner compartment or chamber C or a series o f compartments C C C2, arranged concentrically. Annular spaces are left between the walls of the compartments for the passage of the exhaustgases. In order to break up the gases into ine streams and prevent vibration of the walls of the chamber from being communicated to the atmosphere, the annular spaces are packed, preferably, with steel shavings D, or other suitable material may be employed for this purpose.

The end -plate A11 of the chamber A forms the end plate of the concentric compartments at one end and. is' provided with annular flanges A13, which actas centering-pieces to retain the concentric compartments in position. The other end of the=concentric compartments is closed by a plate O3, which is provided With concentric annular iianges similar to those on the plate A11. The bolts A6 pass longitudinally through one of the concentric IOO chambers and through the end plate C3 and are provided at their ends with nuts to secure the end plate in. position.

The valve-spindle B4 is extended through an opening in the end plate C3, in which an adjustable sleeve C4, having a closed outer end,is screwed. Between the end of the sleeve and the end of the spindle is placed a spring O5, the tension of which can be regulated, and thereby the pressure necessary to move the valve, by rotating the sleeve. A jam-nut or collar C6 is provided on the sleeve, and in order to prevent the spindle rotating independently of the sleeve and to support the spindle a pin C" is passed through the walls of the sleeve and through a slot in the spindle.

The gases pass with considerable force and rapidity, and immediately upon their escape the spring closes the non-return valve, causing a partial vacuum to be left in the tlrst silencer or system of pipes between the valve and the cylinder, which has the ettect of withdrawing from the cylinder that portion of the burned products which usually remains. The consequence of this is that the charge next sucked in by the engine is almost if not quite entirely composed of combustible gases, whereby the strength of the engine is materially increased.

The valve-spindle may be provided with a screw portion, on which nuts or collars may be mounted, and a helical spring may be placed between the collars and the end cover C3. In addition to this spring a buffer-spring may be provided and arranged between the end of the casing and a collar on the spindle. After traversing the compartment() the gases pass by openings C8 into the annular space between the walls of the inner concentric compartment and the next one,and after passing along this space enter by openings C9 the annular space between the Walls of the second and third concentric compartments. The gases after traversing this annular space escape by openings C10 to the atmosphere.

What I claim as my invention, and desire to secure by Letters Patent, is-

l. In an exhaust-silencer, the combination of an expansion-chamber, a conduit between the chamber and the engine-cylinder, a series of concentric compartments through which the gases pass successively from the expansion-chamber to the atmosphere and a non-return valve placed between the expansion-chamber and the compartments substantially as set forth.

2. In an exhaust-silencer, the combination ofan expansion-chamberhaving double Walls, of a series of concentric compartments communicating with each other, an end plate for the contiguous ends of the chamber and compartments, a non return valve in said end plate and plates or covers for the other end of the chamber and compartments.

3. In au exhaust-silencer, the combination of an expansion-chamber having double walls,

a series of concentric compartments, communicating with each other, an end plate for the contiguous ends of the chamber and compartments, an automatic non-return valve in said end plate, end plates or covers for the other ends of the chamber and compartments, and bolts and nuts securing the end plates in position.

4. In an exhaust-silencer, the combination of an expansion-chamber having double walls, an inlet-pipe to the chamber, a series of concentric compartments communicating with each other, an end plate for the contiguous ends of the chamber and compartments, annular flanges on each side of said plate, an automatic non-return valve in said end plate, end plates or covers for the other ends of the chamber and compartments, and bolts and nut-s securing the end plates together.

5. In an exhaust-silencer the combination of an expansion-chamber having double walls, packing between the walls of the chamber, a series of concentric compartments communicating with each other, an end plate for the contiguous ends of the chamber and compartments, an automatic non-return valve in the plate, end plates or covers for the other ends of the chamber and compartments, bolts and nuts securing the end plates together substantially as set forth.

6. In an exhaust-silencer the combination of an expansion-chamber having double walls, packing between the walls of the chamber, a series of concentric compartments communicating with each other, and having annular spaces between them through which the gases pass in a zigzag manner an end plate for the contiguous ends of the chamber and compartments, a non-return valve in the plate, end plates or covers for the other ends of the chamber and compartments, bolts and nuts securing the end plates together, substantially as set forth.

7. In an exhaust-silencer the combination of an expansion-chamber having double walls, packing between the walls of the chamber, a series of concentric compartments communicating with each other, and having annular spaces between them, an end plate for the contiguous ends of the chamber and compartments, a non-return valve in the plate, end plates or covers for the other ends of the chamber and compartments, annular anges on the plates, bolts and nuts securing the end plates together, substantially as set forth.

8. In an exhaust-silencer the combination of an expansion-chamber having double Walls, packing between the walls of the chamber, a series of concentric compartments communicating with each other and the inner of which communicates with the expansion-chamber and the outer with the atmosphere, means for splitting up the exhaust-gases into broken streams when passing along the annular spaces between the concentric compartments, an end plate for the contiguous ends of the chamber and compartments, a non-return ICO IIO

valve in the end plate, end plates or covers c for the other ends of the chamber and compartments and bolts and nuts securing the end plates together substantially as set forth.

9. In an exhaust-silencer the combination of an expansion-chamber having double walls, packing between the walls of the chamber, a series of concentric compartments communieating with each other and the inner of which communicates with the expansion-chamber and the outer with the atmosphere, metal shavings in the annular spaces between the concentric compartments, an end plate for the contiguous end of the chamber and compartments, a non-return valve in the end plate, end plates or covers for the other ends of the chamber and compartments and bolts and nuts securing the end plates together substantially as set forth.

l0. In an exhaust-silencer the combination with the expansion-chamber, the concentric compartments, the plate between the chamber and the compartments, of a cylindrical valve adapted to slide in an opening in the plate and provided with openings in one end and around its periphery a valve-spindle connected to the valve, a spring for the valvespindle and means for regulating the tension of the spring substantially as set forth.

l1. In an exhaust-silencer the combination with the expansion-chamber, the concentric compartments, the plate between the chamber and the compartments, of a cylindrical valve adapted to slide in an opening in the plate and provided with openings in one end and around its periphery, avalve-spindle connected to the valve, an adjustable sleeve in which the end of the valve-spindle slides, a spring situated between the end of the valvespindle and the end of the sleeve and means for regulating the tension of the spring substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

MIDDLETON CRAWFORD.

Witnesses:

HARRY S. BRIDGES, WM. J. DOW. 

